Some people may find when making purple sweet potato congee that the finished congee turns blue. Is it because the purple sweet potato has gone bad or because it was deceived by unscrupulous merchants? In fact, it is not like that. The reason why it turns blue is because of the excessive oxidation of purple sweet potatoes, which is caused by anthocyanin. As long as it is not left overnight, the freshly made purple sweet potato congee is completely safe to eat, and there is no need to worry about spoilage.

It is edible as long as it is not left overnight.

It is a common phenomenon for purple sweet potato congee to turn blue, and many people will encounter this situation. It is mainly caused by anthocyanin, not harmful substances, and it is still edible.

How to prevent purple sweet potato congee from turning blue

The method to prevent purple sweet potato congee from turning blue is:

1. The purple sweet potato congee turns blue because it is rich in anthocyanin.

2. Anthocyanin, this kind of natural pigment, is purple in a neutral environment, purple-red in an acidic environment, and slightly blue in an alkaline environment. Generally, purple sweet potato congee and other dishes are easily turned blue or even green due to water or other reasons.

It only takes a little white vinegar or lemon juice and other acidic liquids to turn it back into purple.

The benefits of purple sweet potato congee

1. Purple sweet potatoes are rich in protein, including 8 amino acids, which are easily digested and absorbed by the human body.

2. Purple sweet potatoes are rich in vitamins A, B, C, and other essential nutrients for the human body.

3. Purple sweet potatoes are rich in fiber, which can promote digestion, improve gastrointestinal function, and prevent the occurrence of gastrointestinal diseases.